JPH0133189Y2 - - Google Patents

Description

[Detailed Description of the Invention] <Industrial Field of Application> This invention relates to an apparatus for optically sorting grains of rice, wheat, beans, etc. according to the color tone of their surfaces.

<Prior Art> Devices have already been proposed for sorting out abnormal grains contained in grains based on differences in surface color. For example, in JP-A-52-35688, grains to be sorted are made to flow down the surface of a single chute arranged in an inclined manner, and a beam of light is irradiated onto the grains at a position protruding from the lower end of the chute. , examine the reflected light from the grain, and if there is an abnormality in the amount of reflected light,
A sorting device is shown that uses an air gun or a jet of air to blow away the abnormal particles. Also,
A method using such an optical sorting method for sorting tea leaves is shown in Japanese Patent Application Laid-Open No. 73378/1983.

<Problems to be Solved by the Invention> However, all of the conventional apparatuses described above use a chute to accelerate the objects to be sorted. This chute is arranged in an inclined manner, and the material to be sorted flows down on its surface, but in order to obtain the required sufficient flow velocity, it is necessary to make the chute long. In addition, quantitative adjustment is required to feed the material to be sorted to the upper end of the chute, and direct feeding from the outlet of the storage tank is not possible.Usually, a vibrating conveyor or the like is used to properly feed the material to be sorted. We are distributing and adjusting supply. As described above, the apparatus using the conventional chute has the disadvantage that the chute is long and a separate vibrating conveyor is required, making the entire apparatus large and expensive.

In view of the above-mentioned drawbacks, the present invention aims to provide an optical grain sorting device that does not use a chute and utilizes natural fall to reduce the size of the device and the manufacturing cost. .

<Means for solving the problem> The technical means of the optical sorting device of the present invention consists of a dropping device that continuously drops grains, and a dropping device that allows grains to fall naturally from this dropping device and reach the discrimination position. A lamp that irradiates the grains with light, a back screen located behind the discrimination position, a light receiving detector that receives reflected light from the grains and the back screen, and a light receiving detector installed near the grain falling area. The dropping device has a hopper shape with an opening at the lower end, and this opening is wide in the width direction and narrow in the thickness direction, so that the grains are thin and , so as to fall over a wide band-shaped area, and a plurality of light detection devices and air guns are installed in parallel to detect light reception in each small area divided in the width direction, and to sort out the blast. It's what I did.

<Operation> In the optical sorting device of the present invention, grains to be sorted are supplied to the dropping device. Since this dropping device is in the form of a hopper, grains can be supplied to the dropping device directly from the outlet of the storage tank.
There is an opening at the bottom of the drop device, so
The grains fall sequentially through this opening. The opening is wide in the width direction and narrow in the thickness direction, so that the grains fall in a band-like area. In addition, since the dimension of the opening in the thickness direction is very narrow, when grains pass through this opening, two grains are not perfectly lined up in the thickness direction, and each grain is pass with slight positional deviations from each other in the vertical direction. The grains that exit the opening fall naturally due to their own weight. As the falling speed increases, the vertical displacement between particles increases, the particles become dispersed, and two particles no longer overlap in the thickness direction. The grains dropped in this manner reach the determination position where they are irradiated with light from the lamp. At the same time, the back screen is also irradiated with light. The light reflected from the grain and the back screen is compared and inspected by a light receiving and detecting device, and if there is a difference in the amount of light between the two, a signal indicating that an abnormal grain has been detected is issued. The amount of light reflected from the back screen is matched to the amount of light reflected from normal grains.On the other hand, if the sorted particles have an abnormal surface color tone, the amount of light reflected from that particle will increase or decrease, so the amount of light from both By comparing the values, it becomes possible to discover abnormal grains. A signal from the light detection device that detects abnormal particles is sent to an air gun, and the abnormal particles are blown away by a jet of air. Note that this light reception detection and jet wind removal are performed for each small area divided in the width direction.

<Example> An example of the sorting device of the present invention will be described below with reference to the drawings. 1 is a dropping device connected to the lower part of the grain A storage hopper. As shown in FIG. 2, the opening 2 of the dropping device 1 has an elongated shape with a narrow width X in the front-rear direction and a long width Y in the left-right direction. The actual dimensions of the widths X and Y are determined appropriately depending on the shape of the grains to be sorted, especially the particle size. For example, in the case of rice, the front and rear widths X should be 10 mm or less, and the left and right widths Y should be It is preferable to make it 20mm or more.
Note that if the front and rear widths X are increased, the particles will overlap each other during discrimination, making highly accurate sorting impossible. Further, the width Y in the left-right direction is determined by taking into consideration the capability of the detection device in the width direction. Reference numerals 3a and 3b indicate light irradiation lamps, which are provided on both sides of the falling flow layer of grains. In addition, a plurality of these lamps may be installed side by side, or a long lamp such as a fluorescent lamp may be used so that the light beam is emitted evenly in the left and right width directions. The particles that have reached the discrimination position P are irradiated with light by the lamps 3a and 3b. Note that the distance from the lower end opening 2 of the drop position 1 to the discrimination position is preferably about 10 cm to 1 m. If the falling distance is short, the falling speed of the particles at the discrimination position is slow, and the distance between particles does not increase.
Particles cannot be sufficiently dispersed, making it impossible to perform highly accurate sorting, and if the falling distance is too long, the turbulence of the falling flow layer becomes large. 4a, 4
b is the back screen, lamp 3 on the same side
They are each irradiated with light from a and 3b. The surface color tone of the back screens 4a and 4b is set so that the amount of light reflected from the back screens matches the amount of light reflected from normal grains. 5a, 5b
is a light receiving and detecting device, and 6a and 6b are lenses. The light receiving and detecting device 5a on the front side detects the reflected light irradiated onto the particles from the lamp 3a and the back screen 4b on the back side.
It receives both the reflected light that has passed through the discrimination position and the reflected light that has arrived, and if there is a difference in the amount of light of both reflected lights, an abnormality is detected. In addition, the light receiving detection device 5a on the back side
symmetrically detects the reflected light on the opposite side. A photoelectric element such as a photodiode is usually used as the light detection device. In addition, the light receiving detection device 5
A and 5b are constructed by providing a plurality of sensing elements in parallel, and each sensing element operates independently. That is, each detection element is in charge of one small area that is divided into the discrimination area in the width direction, and operates depending on whether or not abnormal particles are present in the small area. , only the detection elements in charge of that subarea are activated. The number of detecting elements of the light receiving and detecting device, that is, the number of divisions of the discrimination area is usually preferably about 5 to 20, and is determined as appropriate depending on the width of the grain falling flow layer, etc. Reference numeral 7 denotes an air gun, which is installed on the side of the blast sorting position Q below the discrimination position. A plurality of air guns 7, that is, the same number of air guns 7 as there are elements of the light receiving and detecting device, are provided in parallel, and the abnormal particles are blown away in each small area by signals from the light receiving and detecting devices 5a and 5b. The air gun 7 is electrically connected to both the front and back light detection devices 5a and 5b, and is activated by a signal from either of the front and back light detection devices. Lamp covers 8a and 8b serve to prevent light from the lamps on the opposite side from hitting the back screen or the light detection device.

Next, the operation of the device will be explained. The grains A to be sorted are continuously dropped from the lower end opening 2 of the dropping device 1, but since the opening 2 has an elongated shape that is narrow in the front-rear direction and wide in the left-right direction, the grains that fall fall into a band-like shape. It becomes thick and falls like a waterfall. In addition, since the opening 2 of the dropping device 1 is narrowed only in two directions, the particles are narrowed as much as possible in the front-back direction (thickness direction), making measurement easier, and evenly distributed in the left-right direction. do it like this. The particles thus dropped from the opening 2 descend while accelerating due to natural fall, and reach the determination position P. Particles A falling at the discrimination position are detected by the lamps 3a and 3 on the front and back sides.
Upon receiving light irradiation from b, each particle reflects an amount of light corresponding to its respective surface color tone. This reflected light passes through lenses 6a and 6b and passes through the light receiving and detecting device 5.
a, 5b and is compared with the reflected light from the back screens 4a, 4b. Note that this determination is performed for each small area divided in the width direction. Therefore,
When all the particles in the small area are normal particles, the light reflected from each particle is equal to the light reflected from the back screens 4a and 4b, so the light receiving and detecting devices 5a,
5b does not detect any abnormality, and the particles simply fall directly below. On the other hand, if abnormal grains are included in the small area, there will be a difference in reflected light, so the light receiving detection device 5
a and 5b detect an abnormality, a signal is sent to the air gun 8, and at the moment the grains in the small area reach the blast sorting position Q, the air gun 8 injects high-pressure air,
The rice grains in that small area are blown away. Note that since the grains are continuously dropped, the discrimination is also performed continuously, and if an abnormal grain is detected, only that small area is blown away independently.

As described above, in the sorting device of the present invention, the grains to be sorted are continuously allowed to naturally fall from the dropping device having an elongated opening to be sorted, so the thickness of the falling flow layer is thin and the width is wide. The grains can be separated and sorted so that they do not overlap each other, allowing for highly accurate and efficient sorting. In addition, in the present invention, the grains are allowed to fall naturally through the opening of the dropping device,
Since the conventional chute is not used, the device can be made smaller, and there is no need for a vibrating conveyor, and there are advantages in that the discharge port of the storage tank and the dropping device can be directly connected. Furthermore, in the present invention, the sorting is divided into small areas and is performed for each area, so that the sorting work can be performed with high precision and efficiency.

[Brief explanation of the drawing]

The drawings show an embodiment of the sorting device of the present invention.
The figure is a side view schematically showing the device, FIG. 2 is a perspective view of the opening of the dropping device, and FIG. 3 is a perspective view showing the sorting state. 1...Drop device, 2...Opening, 3...Lamp,
4...Back screen, 5...Light reception detection device,
6...Lens, 7...Air gun, 8...Lamp cover.

Claims (1)

[Scope of utility model registration request] A dropping device that continuously drops the grains, a lamp that irradiates light beams onto the grains that have naturally fallen from the dropping device and reached the discrimination position, a back screen located behind the discrimination position, and a a light receiving detection device that receives reflected light from the back screen;
an air gun installed near the grain falling area and activated by a signal from a light receiving detection device, the dropping device having a hopper shape with an opening at the lower end,
This opening is wide in the width direction and narrow in the thickness direction, so that the grains fall in a thin and wide belt-like area, and multiple light detection devices and air guns are installed in parallel. What is claimed is: 1. An optical sorting device for grains, characterized in that the grains are divided into small areas in the width direction, receive and detect light, and perform blast sorting.